LONDON  Sen. John McCain met Thursday with British Prime Minister Gordon Brown and told reporters afterwards that "al-Qaeda is on the run" in Iraq.

As the war in Iraq enters its sixth year, McCain said the "surge" in U.S. troop levels is bringing stability to Iraq and that the strategy must continue.

"Al-Qaeda is on the run — but not defeated," he said outside the prime minister's residence at 10 Downing Street.

McCain, the presumptive Republican presidential nominee, warned against a precipitous pullout from Iraq that would allow al-Qaeda to declare victory. He said it was important to "see this strategy through to success."

McCain thanked Britain for its support in Iraq and for "the enormous service and sacrifice" that its military men and women have made there and in Afghanistan.

He acknowledged that Britons, along with Americans, were sometimes "frustrated by our lack of progress" in Iraq but insisted the situation had "improved dramatically" in the last year.

Britain has remained the U.S. government's closest ally in Iraq, although its continued military presence there is unpopular at home. It currently has about 4,000 troops stationed in southern Iraq but plans to reduce that to about 2,500 later this year if conditions allow. It has reduced troop levels over the last two years, as its military commitment in Afghanistan has increased.

McCain said he was meeting with the Labor Party prime minister as a senator and as a senior member of the Senate Armed Services Committee, not as a Republican presidential candidate.

He said he admired Brown and appreciated the prime minister's commitment to maintaining the "unique relationship" that exists between the United States and Great Britain.

McCain also applauded Brown's leading efforts on climate change and said he hoped that new global limits on greenhouse gases could be reached with China and India.

The senator was scheduled to meet with opposition Conservative leader David Cameron next before traveling to Paris to meet with pro-American French President Nicolas Sarkozy.

McCain has been on a week-long foreign "fact-finding" tour that has taken him to Iraq for the eighth time, and to Jordan and Israel.

With him at Downing Street were Sens. Joseph Lieberman, I-Conn., and Lindsey Graham, R-S.C., who support his presidential bid.

Lieberman told reporters that McCain was "a steadfast internationalist" who was dedicated to working with other nations around the globe to solve economic, political and environmental problems.

In response to McCain's visit, Democrats Abroad, the Democratic Party's arm that represents Americans living overseas, released a statement saying that "while John McCain travels abroad to try to look presidential, Democrats know that the next president will have hard work to improve America's standing around the world."

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